An electrophoretic device of the initially mentioned kind is described e.g. in U.S. Pat. No. 6,639,580 B1, and may be used to obtain a low-power, optionally reflective, thin display which may be capable to replace paper printouts in many applications.
One problem with the electrophoretic device of the initially mentioned kind is that the contrast may be low, i.e. the brightness difference between written and non-written cells may be low.